Modular hydraulic hammer reduction system for railroad tank cars

ABSTRACT

A modular hydraulic hammer reduction system for railroad tank cars includes tubular hydraulic hammer reduction devices which include means to connect the tubular devices to flanges other than by welding or being cast together. For example, the tubular devices can be press fit into the flanges, or the tubular devices can be connected to the flanges with snap rings (preferably spiral-lock snap rings), or even more preferably the tubular devices can be press fit into the flanges and the tubular devices can be connected to the flanges with snap rings (preferably spiral-lock snap rings). The advantage of this modular construction is that one can manufacture multiple tubular devices and multiple flanges of each type, and connect the flanges to the tubular devices on an as-needed basis. This is preferable to having many of each type of hydraulic hammer reduction system assembled and ready to be delivered, as the demand for different types of hydraulic hammer reduction systems varies and storing fully assembled devices will take up more space.

CROSS-REFERENCE TO RELATED APPLICATIONS

Priority of our U.S. Provisional Patent Application Ser. No. 61/509,431,filed 19 Jul. 2011, incorporated herein by reference, is hereby claimed.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable

REFERENCE TO A “MICROFICHE APPENDIX”

Not applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to hydraulic hammer reduction system forrailroad tank cars.

2. General Background of the Invention

Prior U.S. Pat. Nos. 4,840,192 and 4,938,247 disclose a hydraulic hammerreduction system for railroad tank cars. This original hydraulic hammerreduction system for railroad tank cars included devices which were castas one piece or welded together (typically, they were made in two parts,the flange and the cylinder, and the flange and the cylinder were pressfit together, then welded together). These are still commerciallyavailable from Industrial Pump Sales, Inc., 2814 Engineers Road, BelleChasse, LA 70037, US. Also commercially available from Industrial PumpSales, Inc. is a plastic hydraulic hammer reduction system described inU.S. Pat. No. 6,382,233.

U.S. Pat. No. 5,785,078 shows a safety vent for a railroad tank carwhich has a housing mounted about an opening on the top of the car. Thehousing body defines a cavity which contains a surge protector and arupture disk.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a modular hydraulic hammer reductionsystem for railroad tank cars. The modular hydraulic hammer reductionsystem for railroad tank cars includes tubular hydraulic hammerreduction devices (which can in all respects be like those shown inprior U.S. Pat. Nos. 4,840,192 and 4,938,247) which include means toconnect the tubular devices to flanges other than by welding or beingcast together. For example, the tubular devices can be press fit intothe flanges, or the tubular devices can be connected to the flanges withsnap rings (preferably spiral-lock snap rings), or even more preferablythe tubular devices can be press fit into the flanges and the tubulardevices can be connected to the flanges with snap rings (preferablyspiral-lock snap rings). The advantage of this modular construction isthat one can manufacture multiple tubular devices and multiple flangesof each type, and connect the flanges to the tubular devices on anas-needed basis. This is preferable to having many of each type ofhydraulic hammer reduction system assembled and ready to be delivered,as the demand for different types of hydraulic hammer reduction systemsvaries and storing fully assembled devices will take up more space.

It is preferable not to weld the flange and the cylinder together, asthe welding procedures are complicated, and typically add about an hourof time per completed unit compared to the new preferred systemdisclosed herein for joining the flange to the cylinder.

Though preferably the tubular devices are press fit into the flanges andthe tubular devices are connected to the flanges with snap rings(preferably spiral-lock snap rings), other means of connecting thetubular devices to flanges other than by welding or being cast togetherinclude: threads (threading the body and the flange and screwing themtogether), interference fit, friction fit, dovetail (or taper fit—usinga taper on the body that corresponds to a taper on the flange), slip-onfit from top of flange that would include a register in the flange and amale boss on the body, and press-fit between the body and flange securedby a product-appropriate epoxy glue.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a further understanding of the nature, objects, and advantages ofthe present invention, reference should be had to the following detaileddescription, read in conjunction with the following drawings, whereinlike reference numerals denote like elements and wherein:

FIG. 1 is a detail of a preferred embodiment of the apparatus of thepresent invention;

FIG. 2 is an elevation view of a common railroad tank car vehiclecontaining a preferred embodiment of the apparatus of the presentinvention;

FIG. 3 is an exploded view of a preferred embodiment of the apparatus ofthe present invention;

FIG. 4 is a perspective view of a preferred embodiment of the apparatusof the present invention;

FIG. 5 is a detail designated as A in FIG. 4 showing a preferredembodiment of the apparatus of the present invention;

FIG. 6 shows a flange of a preferred embodiment of the apparatus of thepresent invention;

FIG. 7 shows a flange of a preferred embodiment of the apparatus of thepresent invention;

FIG. 8 shows a flange of a preferred embodiment of the apparatus of thepresent invention;

FIG. 9 shows a flange of a preferred embodiment of the apparatus of thepresent invention;

FIG. 10 is an end view of a baffle of a preferred embodiment of theapparatus of the present invention;

FIG. 11 is a side view of a baffle of a preferred embodiment of theapparatus of the present invention;

FIG. 12 is a detail designated as B in FIG. 11 of a baffle of apreferred embodiment of the apparatus of the present invention;

FIG. 13 is a perspective view of a baffle of a preferred embodiment ofthe apparatus of the present invention;

FIG. 14 is a top view of a flange of a preferred embodiment of theapparatus of the present invention;

FIG. 15 is a side view of a preferred embodiment of the apparatus of thepresent invention;

FIG. 16 is a detail designated as D in FIG. 17 of a cutaway of apreferred embodiment of the apparatus of the present invention;

FIG. 17 is a cutaway view designated as C-C in FIG. 15 of a preferredembodiment of the apparatus of the present invention;

FIG. 18 is a perspective view of a preferred embodiment of the apparatusof the present invention;

FIG. 19 is a top view of a flange of a preferred embodiment of theapparatus of the present invention;

FIG. 20 is a side view of a preferred embodiment of the apparatus of thepresent invention;

FIG. 21 is a detail designated as F in FIG. 22 of a cutaway of apreferred embodiment of the apparatus of the present invention;

FIG. 22 is a cutaway view designated as E-E in FIG. 20 of a preferredembodiment of the apparatus of the present invention;

FIG. 23 is a perspective view of a preferred embodiment of the apparatusof the present invention;

FIG. 24 is a top view of a flange of a preferred embodiment of theapparatus of the present invention;

FIG. 25 is a side view of a preferred embodiment of the apparatus of thepresent invention;

FIG. 26 is a detail designated as H in FIG. 27 of a cutaway of apreferred embodiment of the apparatus of the present invention;

FIG. 27 is a cutaway view designated as G-G in FIG. 25 of a preferredembodiment of the apparatus of the present invention;

FIG. 28 is a perspective view of a preferred embodiment of the apparatusof the present invention; and

FIG. 29 shows a triangular flange of a preferred embodiment of theapparatus of the present invention.

DETAILED DESCRIPTION OF PREFERRED, EXEMPLARY EMBODIMENTS

A preferred, exemplary application of the hydraulic hammer reductionsystem of the present invention is railroad tank cars, an exemplary oneof which is illustrated in FIG. 2. As can be seen in that figure, arupture disk assembly 9 is included as a standard item leading into thetank 6 of the railroad car.

As is known, the standard rupture disk assembly 9, such as thatillustrated in FIGS. 1 & 2, is a safety device which allows a relativelysmall amount of the liquid load to escape by rupturing the disk in thedisk assembly 9, when there is a surge in the liquid load, as forexample when the tank car is brought to a sudden stop or when there is aBLEVE (boiling liquid expanding vapor explosion) due to fire. Thisallows part of the cargo to escape in order to save the tank itself fromrupturing, causing the possible escape of the entire load, possiblygreatly endangering the environment.

As is best shown in FIG. 1, a preferred, exemplary embodiment of thehydraulic hammer reduction damper 100 of the present invention includesa flange 305 for connecting it to the like plate or flange 15 of thestandard nozzle attachment 7 provided for the rupture disc assembly 9(as shown in FIG. 1). The flange plates 305, 15 comprise flat, circularplates directly or indirectly attached to and extending around but notblocking the top opening of the cylinder or basic pipe-body 1 of thedamper 100. Flange plate 305 can have an outer diameter in the range of3 to 13 inches (7.62 to 33.02 cm), for example 8 inches (20.32 cm); aninner diameter in the range of 2 to 4 inches (5.08 to 10.16 cm), forexample 2 inches (5.08 cm); and a height or thickness in the range of ½to ¾ inches (1.27 to 1.905 cm), for example ⅝ inches (1.588 cm).

Flange plate 15 can have an outer diameter in the range of 3 to 13inches (7.62 to 33.02 cm), for example 8 inches (20.32 cm); an innerdiameter in the range of 3 to 6.5 inches (7.62 to 16.51 cm), for example8 inches (20.32 cm; and a height or thickness in the range of ½ to ¾inches (1.27 to 1.905 cm), for example ⅝ inches (1.588 cm)cm). Standardnozzle attachment 7 can have, for example, a diameter of 3 to 6.5 inches(7.62 to 16.51 cm), for example. All of these parts in this paragraphare part of the tank car, and comprise its attachment point to thesystem of the present invention.

The cylinder or pipe body of the damper body 1 in the exemplaryembodiment illustrated extends about ten inches below the flange 305,though it could extend about 10.25 to 10.5 inches (26.04 to 26.67 cm)below the flange 305. A pressure relief or vacuum-break port 12 (seeFIG. 3) is located about 1.5 inches (3.81 cm) below the flange 305,though port 12 could be for example located about 1.15 to 1.25 inches(2.92 to 3.18 cm) below the flange 305. The pressure relief orvacuum-break port 12 (which may be better described as a “bypass port”required by Transport Canada) can have a diameter of about ½ to 1 inch(1.27 to 2.54 cm), for example 1 inch (2.54 cm).

The interior of the cylindrical pipe body 1 has affixed to it asuccession or series of upwardly directed, flat baffle plates 2 on bothsides, constructed of stainless steel or some other suitable material,each separately welded into place (or cast in place) at for example a 30degree angle up from the horizontal (though the angle for example couldbe −45 to +45 degrees up from horizontal). Each baffle plate 2preferably has a drain hole 11 at its lowest point (see FIGS. 10, 14,17, 19, 22, 24, and 27). The energy dissipation or baffle plate 2 canfor example be made of ⅛ to ⅜ inch (3.18 to 9.53 mm) plate spaced 1.5 to2 inches (3.81 to 5.08 cm) apart on opposite sides of the body 1. Forexample, each energy dissipation or baffle plate 2 can be made of ¼ inchplate (0.64 cm) spaced 1.5 inches (3.81 cm) apart on opposite sides ofthe body 1. The drain hole 11 can have a diameter of ¼ to ½ inch (0.635to 1.27 cm), for example ⅜ inch (0.9525 cm).

As can best be seen in FIGS. 1, 17, 22, & 27, each baffle plate 2preferably extends past the center or axis line of the cylindrical pipebody 1, covering more than half of the horizontal cross-section of thebody 1. The diameter of pipe body 1 could be, for example 2 to 4 inches(5.08 to 10.16 cm), and the baffle plates 2 may extend out horizontallyfor example 1 to 2 inches (2.54 to 5.08 cm). With an exemplary diameterof 2.375 inches (6.03 cm) for the pipe body 1, the baffle plates 2 mayextend out horizontally 1.25 inches (3.18 cm), for example.

As illustrated in FIG. 1, the standard rupture disc assembly 9 (seeFIG. 1) has a flange 45 which connects to the flange 305 and flange 15with bolts 47 and nuts 46. Bolts 47 can have dimensions of ½ to ¾ inch(1.27 to 1.905 cm), for example ⅝ inch (1.588 cm). Nuts 46 can havedimensions of ½ to ¾ inch (1.27 to 1.905 cm), for example ⅝ inch (1.588cm). Thus, dependent on the size of the nuts 46 and bolts 47, the flangebolt holes 14 can vary in diameter from 11/16 to ⅞ inch (1.746 to 2.222cm), for example, ⅝ inch (1.588 cm). The lower end 3 of the cylinder 1,or the end further from the flange plate 5, is open and unobstructed(see FIG. 17), as is the upper end 4 of the cylinder 1; this allowsfluid to flow into the lower end 3 of cylinder 1 and out of the top end4 of cylinder 1.

When the damper 100 extends down into the tank 6 of the railroad carabout 9 inches with a cylindrical body having a diameter of 2.375 inchesit occupies only approximately 40 cubic inches (about 0.17 gallons-0.643liters) of space in the tank 6, which typically has a capacity of 12,000to 15,000 gallons (45,425 to 56,781 liters). The device 100 thusoccupies less than 0.25 of a gallon (0.946 liters), which is far lessthan 1% of the total volume, far less than 0.1% of the total volume,less than 0.01% of the total volume and only about 0.001% of the totalvolume.

The measurements, materials, and angles noted herein may varysubstantially depending upon the application and future designrefinements.

Operation of Over-all System

As is best shown in FIG. 1, the flange 45 of the rupture disk assembly9, the flange 305 of the damper 100, and the flange 15 of the tank car 6are secured to one another by way of four nuts 46 and bolts 47 using theflange bolt holes 14 and a gasket 51 between flange 45 and flange 305and a gasket 52 between flange 305 and flange 15, creating an air-tightseal. Gaskets 51 and 52 can for example be about 1/16 inch (0.159 mm)thick and be made of suitable material, such as rubber,polytetrafluoroethylene, asbestos, asbestos replacements, Garlock® brandgraphite-based material, and Gylon® PTFE-based materials. Flange plate45 can have an outer diameter in the range of 3 to 13 inches (7.62 to33.02 cm), for example 8 inches (20.32 cm); an inner diameter in therange of 2 to 4 inches (5.08 to 10.16 cm), for example, 2 inches (5.08cm); and a height or thickness in the range of ½ to ¾ inch (1.27 to1.905 cm), for example ⅝ inch (1.588 cm). Gaskets 51 and 52 can have,for example, an inside diameter of 2 to 7 inches (5.08 to 17.78 cm), forexample, 2 inches (5.08 cm), an outside diameter of 4¾ to 9.75 inches(12.065 to 24.765 cm), for example, 2″ ID×5.125″ OD (5.08 cm ID×13.017cm OD), and a height or thickness of 1/16 to ¼ inch (0.159 to 0.635 cm),for example, 1/16 inch (0.159 cm). The open end 4 of the cylinder 1projects into the tank car 6, the body 1 being nested within and carriedby the standard nozzle 7 of the rupture disk system. Screwed onto thethreads 3 of the damper 100 is the rupture disk assembly 9.

When the motion of a tank car 6 is increased or decreased abruptly,hydraulic hammer pressure is created, a force whereby the liquid insidethe tank car begins to release substantial kinetic energy. The liquid atthis point enters the open, lower end 3 of the hydraulic damper 100.

As is best shown in FIG. 17, the liquid, after entering the opening 3,encounters the energy dissipating baffle plates 2, and is therebydiverted from one side of the cylinder 1 to the other (note directionarrows 21 of FIG. 17), while still being allowed to pass upwardlythrough the length of the damper 100 with sufficient speed and volume toprevent tank fracture pressures from occurring. Each time the liquidencounters a baffle plate 2 and is diverted from one baffle plate 2 toanother, the kinetic energy of the liquid is diminished or dissipated.The pressure relief port or vacuum-break 12 allows the air initially inthe cylinder 1 to be relieved or moved into the top of the tank car 6 asthe liquid displaces it in its upward journey.

Ideally, by the time the liquid reaches the upper end of the hydraulicdamper 100, the pressure or kinetic energy of the liquid is diminishedto a pressure below the working or breaking pressure of the rupture disk(not shown) of the assembly 9, preventing its rupture. If the pressureis reduced sufficiently, the liquid will then drain back into the tankvia the drain holes 11.

On the other hand, if the pressure or kinetic energy of the liquid isnot reached sufficiently, that is, the pressure is still great enough tofracture the rupture disk of the assembly 9 after having passed throughthe damper 100, it will rupture, allowing the escape of a portion of theliquid load and relieving the excess pressure before fracturing of thetank 6 itself occurs. Thus, the ultimate fail-safe aspects of therupture disk assembly 9 are still maintained with the present invention.

However, the presence of the damper 100 prevents rupturing of the diskin most, if not all cases, at least usually preventing the escape of anyof the liquid load, which otherwise would have occurred, preventing anyloss of the load and any damage to the environment.

The kinetic energy of the moving liquid load can be mechanicallydissipated by many other forms and configurations of the damper of thepresent invention. Although the particular configuration and structuredisclosed and illustrated is reliable, relatively easy to manufactureand economical, other shapes, sizes and configurations are of coursepossible. For example, the flow path can be made even more convoluted,openings or grates could be included, roughened surfaces or protrusionsprovided, varying size and configurations in cross-sections could beused as the damper is traversed, etc.

Additionally, the preferred application of the present invention israilroad tank cars, tank trucks, or other liquid load carriers and thelike, in which a liquid load is being transported from one point toanother in a tank, subject to abrupt changes in speed. However, theprinciples of the present invention can be applied to otherapplications, such as, for further example, a vertical turbine pumpprior to or in place of a mechanical seal, etc.

FIG. 3 is an exploded view of a preferred embodiment of the apparatus ofthe present invention, designated generally by the numeral 10. Hydraulichammer reduction device 10 includes a flange 5, a baffle 20, and anoptional spiral-lock snap-ring 40. Flange 5 (FIGS. 3, 4, and 6) includesan optional snap-ring recess 35 and flange bolt holes 14. Flange 5 isgenerally square but has cut-off corners 106. Flange 5 can have, a widthof 6.4 to 6.6 inches (16.256 to 16.764 cm), for example, 6.5 inches(16.51 cm); an inner diameter of 2.25 to 2.375 inches (5.715 to 6.032cm), for example, 2¼ inches (5.715 cm); and a height or thickness of ½to ¾ inch (1.27 to 1.905 cm), for example ⅝ inch (1.588 cm). The cut-offcorners 106 of flange 105 are preferably rounded to 3 to 13 inches (7.62to 33.02 cm), for example 8″ (20.32 cm).

Optional snap ring recess 35 of flange 5 can have a depth from 0.090 to0.160 inches (0.229 to 0.406 cm), for example 0.125 inches (0.317 cm);an inner diameter of 2.31 to 2.35 inches (5.867 to 5.969 cm), forexample 2.58 inches (6.553 cm); and an outer diameter of 2.58 to 2.68inches (6.553 to 6.807 cm), for example 2.58 inches (6.553 cm). Baffle20 includes a pressure relief/vacuum-break port 12, baffle plates 2, areduced-outer-diameter neck 22, and an optional snap-ring groove 25.Reduced-outer-diameter neck 22 can have an inner diameter of 1.9 to 2inches (4.826 to 5.08 cm), for example 2 inches (5.08 cm); an outerdiameter of 2.312 to 2.315 inches (5.872 to 5.880 cm), for example,2.312 inches (5.872 cm); and a height of 0.6 to 0.625 inch (1.524 to1.587 cm), for example 0.625 inch (1.587 cm). Optional snap-ring groove25 can have a depth of 0.04 to 0.06 inch (0.102 to 0.152 cm), forexample 0.05 inch (0.127cm); an inner diameter of 2.2 to 2.21 inches(5.588 to 5.613 cm), for example 2.21 inches (5.613 cm); and an outerdiameter of 2.29 to 2.3 inches (5.816 to 5.842 cm), for example 2.3inches (5.842 cm).

Optional snap-ring 40 is used to connect baffle 20 to flange 5, eitherby itself, or after the baffle 20 has already been press fit to flange5. Optional snap-ring 40 can have an inner diameter of 2.23 to 2.25inches (5.664 to 5.715 cm), for example, 2.25 inches (5.715 cm); anouter diameter of 2.5 to 2.52 inches (6.35 to 6.40 cm), for example 2.5inches (6.35 cm); and a height of 0.060 to 0.070 inches (0.152 to 0.178cm), for example, 0.060 inches (0.152 cm). Baffle 20 can be press fit toflange 5 without the use of the snap-ring 40.

Flanges 105, 205, and 305 are variations of and serve the same purposeas flange 5, and are designed to match flanges of the shapes shown.Flange 105 (FIG. 7) is generally square but has cut-off corners 106 andincludes a groove 37 for receiving a rupture disk holder that isequipped with a tongue (or male register) for centering the holder.Flange 105 can have width of 6.4 to 6.6 inches (16.256 to 16.764 cm),for example, 6.5 inches (16.51 cm); an inner diameter of 2.25 to 2.375inches (5.715 to 6.032 cm), for example, 2¼ inches (5.715 cm); and aheight or thickness of ½ to ¾ inch (1.27 to 1.905 cm), for example ⅝inch (1.588 cm). The cut-off corners 106 of flange 105 are preferablyrounded to 3 to 13 inches (7.62 to 33.02 cm), for example 8″ (20.32 cm).The groove 37 of flange 105 can have an inner diameter from 3.98 to 3.99inches (10.109 to 10.135 cm), for example, 3.99 inches (10.135 cm); anouter diameter of 4.755 to 4.76 inches (12.077 to 12.090 cm), forexample, 4.755 inches (12.077 cm); and a depth of 0.180 to 0.190 inches(0.457 to 0.483 cm), for example, 0.188 inches (0.478 cm). Flange 205(FIG. 8) is also generally square and has cut-off corners 106. Flange205 can have a width of 6.4 to 6.6 inches (16.256 to 16.764 cm), forexample, 6.5 inches (16.51 cm); an inner diameter of 2.25 to 2.375inches (5.715 to 6.032 cm), for example, 2¼ inches (5.715 cm); and aheight or thickness of ½ to ¾ inches (1.27 to 1.905 cm), for example ⅝inches (1.588 cm). The cut-off corners 106 of flange 105 are preferablyrounded to 3 to 13 inches (7.62 to 33.02 cm), for example 8″ (20.32 cm).Flange 205 includes an elongated hole 114 facilitating the use of both a4-bolt 6.25″ bolt circle pattern and a 3-bolt 5.5″ bolt circle pattern.Elongated hole 114 can have a diameter of 0.74 to 0.76 inch (1.880 to1.930 cm), for example, 0.75 inch (1.905 cm). Flange 305 (FIG. 9) iscircular. Flange 405 (FIG. 29) is triangular.

FIG. 29 shows a triangular flange 405 of a preferred embodiment of theapparatus of the present invention. Triangular flange 405 might be used,for example, with a triangular shaped rupture disk holder.

The following is a list of parts and materials suitable for use in thepresent invention. Preferably, all parts of the apparatus of the presentinvention are made of stainless steel, and preferably 316 stainlesssteel, though other metals could be used. Plastic could also be used,but is not preferred. Possible plastics and other non-metal materialsinclude Trade name plastics such as Delrin, HYD, Kynar, Pennlon, Ryton,Teflon, UHMW, Ultra Poly AR, plastic families such as acetals, castnylons, extruded nylons, fluoropolymers, polypropylenes, polyethylenes,and polyvinylidene fluoride (PVDF).

Parts List

Part Number Description 1 basic pipe body or cylinder 2 flat baffleplates 3 lower end of cylinder 1 4 upper end of cylinder 1 5 flange 6tank 7 standard nozzle attachment 9 rupture disk assembly 10 hydraulichammer reduction device 11 drain hole 12 pressure relief/vacuum-breakport 14 flange bolt holes 15 flange 20 hydro damp baffle 21 directionarrows 22 neck of baffle 20 25 snap-ring groove 35 snap-ring recess 37groove for receiving a rupture disk holder (seen in FIG. 7) 40spiral-lock snap-ring 45 flange of rupture disk assembly 9 46 nut 47bolt 51 gasket between flange 45 and flange 305 52 gasket between flange305 and flange 15 100 modular hydraulic damping device assembly(including rupture disk - not shown) 105 flange 106 cut-off corners 114elongated hole 205 flange 305 flange 405 flange

All measurements disclosed herein are at standard temperature andpressure, at sea level on Earth, unless indicated otherwise.

The foregoing embodiments are presented by way of example only; thescope of the present invention is to be limited only by the followingclaims.

The scope of the claims should not be limited by the preferredembodiments set forth in the examples, but should be given the broadestinterpretation consistent with the description as a whole.

1. A mechanical energy dissipation system for dissipating hydraulichammer action in a moving tank containing a liquid load, having arupture disk assembly for allowing some of the liquid load to escapefrom the tank before the tank is fractured from the hydraulic hammeraction or BLEVE, comprising: a mechanical device of a relatively smallsize in comparison to the size of the tank, said device being sized andshaped to be located in the line of flow between the rupture disk of therupture disk assembly and the liquid load, in the tank, said device whenlocated in the line of flow presenting impact surfaces to the liquidflow from the tank to the rupture disk, dissipating the hydraulic hammeraction of the liquid as it flows through said device, wherein saiddevice includes a tubular body portion and a flange portion, and thetubular body portion is neither welded to the flange portion nor cast asa unitary unit with the flange portion, and wherein the tubular bodyportion is attached to the flange portion with a press fit. 2-4.(canceled)
 5. The system of claim 1, wherein when located in the line offlow said device occupies less than and extends into less than about 1%of the interior volume of the tank.
 6. The system of claim 1, whereinthe tubular body portion has an interior, and the impact surfacescomprise: a series of baffles in succession affixed to andlongitudinally spaced along opposite sides of the interior of thetubular body portion, said tubular body portion projecting into the tankand out of the tank leading to the rupture disk assembly when the deviceis located in the line of flow.
 7. The system of claim 6, wherein saidbaffles are a series of flat plates affixed to the interior wall of saidtubular body portion angled upwardly from the horizontal when thetubular body portion is oriented vertically.
 8. The system of claim 7,wherein each of said flat plates extends and covers over at least 50% ofthe horizontal cross-section of said tubular body portion.
 9. The systemof claim 7, wherein each of said flat plates has at least one drain holeadjacent its central connection point of its attachment to said tubularbody portion. 10-64. (canceled)
 65. The apparatus of claim 1, furthercomprising the tank.
 66. The apparatus of claim 65, wherein the tank isa railroad tank car.
 67. Apparatus including a mechanical energydissipation system for dissipating hydraulic hammer action in a movingtank containing a liquid load, having a rupture disk assembly forallowing some of the liquid load to escape from the tank before the tankis fractured from the hydraulic hammer action or BLEVE, comprising: amechanical device of a relatively small size in comparison to the sizeof the tank, said device being sized and shaped to be located in theline of flow between the rupture disk of the rupture disk assembly andthe liquid load, in the tank, said device when located in the line offlow presenting impact surfaces to the liquid flow from the tank to therupture disk, dissipating the hydraulic hammer action of the liquid asit flows through said device, wherein said device includes a tubularbody portion and a flange portion, and the tubular body portion is notcast as a unitary unit with the flange portion, and the tubular bodyportion is attached to the flange portion with a press fit.
 68. Theapparatus of claim 67, wherein said device when located in the line offlow occupies less than and extends into less than about 1% of theinterior volume of the tank.
 69. The apparatus of claim 67, wherein thetubular body portion has an interior, and the impact surfaces comprise:a series of baffles in succession affixed to and longitudinally spacedalong opposite sides of the interior of the tubular body portion, saidtubular body portion projecting into the tank and out of the tankleading to the rupture disk assembly when installed in the line of flow.70. The apparatus of claim 69, wherein said baffles are a series of flatplates affixed to the interior wall of said tubular body portion angledupwardly from the horizontal when the tubular body portion is orientedvertically.
 71. The apparatus of claim 70, wherein each of said flatplates extends and covers over at least 50% of the horizontalcross-section of said tubular body portion.
 72. The apparatus of claim70, wherein each of said flat plates has at least one drain holeadjacent its central connection point of its attachment to said tubularbody portion.
 73. The apparatus of claim 67, further comprising thetank.
 74. The apparatus of claim 73, wherein the tank is a railroad tankcar.
 75. Apparatus including a mechanical energy dissipation system fordissipating hydraulic hammer action in a moving tank containing a liquidload, having a rupture disk assembly for allowing some of the liquidload to escape from the tank before the tank is fractured from thehydraulic hammer action or BLEVE, comprising: a mechanical device of arelatively small size in comparison to the size of the tank, said devicebeing sized and shaped to be located in the line of flow between therupture disk of the rupture disk assembly and the liquid load, in thetank, said device when located in the line of flow presenting impactsurfaces to the liquid flow from the tank to the rupture disk,dissipating the hydraulic hammer action of the liquid as it flowsthrough said device, wherein said device includes a tubular body portionand a flange portion, and the tubular body portion is attached to theflange portion with a snap ring.
 76. The apparatus of claim 75, furthercomprising baffles, wherein said baffles are a series of flat platesaffixed to the interior wall of said tubular body portion angledupwardly from the horizontal when the tubular body portion is orientedvertically.
 77. The apparatus of claim 75, further comprising the tank.78. The apparatus of claim 77, wherein the tank is a railroad tank car.